Adrian,
> That's why I said "for appropriate g and f". But I see that my
> wording was misleading.
Thanks for following up! I had thought you were arguing that foldl and
foldr were easily and intuitively interchangeable; they're surely not so
for beginners.
Now I think you're arguing that given strict oplus, each can be generally
expressed in terms of the other, allowing for different space/time
complexity.
Thanks for clarifying. I should have paid more attention to your
"appropriate g and f" qualifier.
Cheers,
John